1. Field of the Invention
The present invention relates to a recording apparatus having a detachable head cartridge, and more particularly to an attaching/detaching mechanism of the head cartridge.
2. Related Background Art
A recording apparatus for recording on a recording medium (hereinafter also called recording sheet) such as paper, cloth, plastic sheet or OHP sheet has been proposed in a form capable of mounting a head cartridge of various recording systems, such as wire dot system, thermosensitive system, thermal transfer system or ink jet system.
Among these recording apparatuses, an apparatus that is equipped with a head cartridge of ink jet type, which performs non-impact recording at a low noise level, forms a record on a recording sheet by discharging ink from a discharge port (nozzle) arranged on a recording element (hereinafter also called an ink jet recording apparatus), and is capable of high-density and high-speed recording.
The ink jet recording apparatus assumes a configuration matching the function, specification, form, etc. peculiar to a system to which the apparatus is applied. In general, the ink jet recording apparatus is provided with a carriage supporting a head cartridge and an ink tank, conveying means for conveying the recording sheet, and control means for controlling these components.
Also the head cartridge for discharging ink droplets from plural discharge ports is driven in a serial scanning motion in a direction (main scanning direction) perpendicular to the conveying direction (sub scanning direction) of the recording sheet, while the recording sheet is intermittently conveyed (pitch conveying) by an amount equal to the recording width. By employing a head cartridge having plural ink discharging nozzles arranged linearly in the sub scanning direction, there is achieved recording of a width corresponding to the number of nozzles by a single scan of the head cartridge on the recording sheet.
Also the ink jet recording apparatus has a low running cost, can be made compact in its dimensions and can achieve color image recording by employing inks of plural colors.
For these reasons, the ink jet recording apparatus is utilized and commercialized as the output means of information processing systems, for example, a printer constituting an output terminal of a copying machine, a facsimile apparatus, an electronic typewriter, a word processor, a work station, etc., or a handy or portable printer equipped in a personal computer, a host computer, an optical disk device, a video apparatus, etc.
As the recording element of such ink jet recording means, namely the energy generating means for generating energy for discharging ink, there have been known, for example, an electromechanical converting member such as a piezo element, utilization of heat generated by irradiation with an electromagnetic wave such as a laser beam to discharging liquid droplet, or heating of liquid by an electrothermal converting element having a heat generating resistance member.
Among these systems, the head cartridge of the ink jet recording system for discharging liquid by thermal energy is capable of recording with high resolution because the aforementioned discharge ports can be arranged at a high density. In particular, the head cartridge utilizing the electrothermal converting element as the energy generating means is advantageous since it can easily be made compact, it can fully utilize semiconductor technology and microprocessing technology which have recently shown remarkable progress and improvement in reliability, and it can achieve a high density with a low manufacturing cost.
Also the ink tank for supplying the head cartridge with ink is basically composed of an ink absorbent member, a container for holding the ink absorbent member, and a cover member for sealing the container.
Also the aforementioned head cartridge can be realized in a chip type integrated with such ink tank, or in a type detachably combined with the ink tank. In either type, the positioning between the recording head and the ink tank, and the positioning between the head cartridge formed by integrating these members and the carriage are important items relating to the recording quality.
Recently there is also proposed a recording apparatus in which plural head cartridges of different external shapes can be detachably attached for replacement onto the carriage. More specifically, a color head is mounted on the carriage for recording color graphics. The color head is composed of plural tanks, respectively containing inks of black, yellow, magenta and cyan colors, detachably mounted on a head. Also a photo head is mounted on the carriage for photographic tone recording. The photo head is composed of plural tanks, respectively containing inks of pale black, yellow, pale magenta and pale cyan colors, detachably mounted on a head. Also in case of recording a text with black color, a black head having a tank of black color only is mounted on the carriage.
The color head, the photo head and the black head are the same in the mechanism for attaching to the carriage and in the shape, but the black head has a smaller width in comparison with the color head or the photo head, because of the lower ink capacity in the tank.
The black head, having a smaller width than in the color head or the photo head, is smaller in width than the carriage. For this reason it can be mounted in an inclined position on the carriage, and the connector portion of the carriage may be smeared by the ink of the nozzle portion of the black head. The ink deposition on the connector portion of the carriage may result in shortcircuiting, leading to drawbacks such as defective recording or malfunction of the recording apparatus.
An object of the present invention is to provide a head cartridge attach/detaching mechanism capable, in mounting a head cartridge of a smaller size with respect to the carriage, of avoiding contact of the recording portion of the head cartridge with the connector portion of the carriage, and also ensuring satisfactory operability.
Another object of the present invention is to provide a carriage of a recording apparatus, comprising a head mounting portion on which the head cartridge is detachably mounted, a connector portion to be electrically connected with the head cartridge, an operating portion adapted, when rotated in a direction, to fix the head cartridge mounted on the head mounting portion and to electrically connect the connector portion while, when rotated in a direction opposite to that in the fixing operation, to release the electrical connection between the head cartridge and the connector portion thereby rendering the head cartridge detachable from or mountable to the head mounting portion, and a connector protecting member adapted to protect the connector portion and, when the operating portion is rotated in a direction rendering the head cartridge detachable or mountable, to move to a position protecting the connector portion, while, when the operating portion is rotated in a direction fixing the head cartridge, to move to a position exposing the connector portion.